Churchill was a powerful weapon because he gave the British people hope with his daily radio addresses. Instead of hiding behind his military he rallied the people of Britain around him, brought them together against a common enemy and did so through the available communications of the day. He was also a gifted public speaker. Before the war Churchill was an unpopular politician within Britain and was generally seen as a failure in a weird way the war made Churchill the epic political figure we know today. His ability to inspire Britain helped to save them. Hope this helps.